soc/intel/skylake: Only reserve TPM area for !CONFIG_TPM_CR50 device

As per PC client TPM specification, the TPM description contains the
base address of the TIS interface 0xfed40000 and the size of
the MMIO area is 20KB (0x5000). Hence ACPI used to reserve those fixed
system memory from getting used by OS.

Platform with TPM_CR50 doesn't require fixed SoC mapped memory hence
additional reservation might not required.

TEST=Build and boot EVE and Soraka to OS.

Change-Id: Id02a2659ce42f705180370000df89d4f6b64afce
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38512
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/skylake/acpi/systemagent.asl

@@ -182,11 +182,13 @@ Method (_CRS, 0, Serialized)
 				0x00000000, PCH_PRESERVED_BASE_ADDRESS, 0xfe7fffff,
 				0x00000000, PCH_PRESERVED_BASE_SIZE)
 
+#if !CONFIG(TPM_CR50)
 		/* TPM Area (0xfed40000-0xfed44fff) */
 		DWordMemory (ResourceProducer, PosDecode, MinFixed, MaxFixed,
 				Cacheable, ReadWrite,
 				0x00000000, 0xfed40000, 0xfed44fff, 0x00000000,
 				0x00005000)
+#endif
 })
 
 	/* Find PCI resource area in MCRS */